I looked for docbook.xsl and found it in several places:
/usr/share/sgml/docbook/xsl-stylesheets-1.50.0-3/fo/docbook.xsl
/usr/share/sgml/docbook/xsl-stylesheets-1.50.0-3/html/docbook.xsl
/usr/share/sgml/docbook/xsl-stylesheets-1.50.0-3/xhtml/ocbook.xsl

Is there some other package I need to build or do I just need to somehow
tell the Subversion build where to find the file it is looking for?